Significance: Nearly half of people living with Alzheimer's disease and related dementias have not been diagnosed. There are many potential benefits of diagnosing these patients, such as connecting them and their families with appropriate support and services. There are also potential risks such as stigma, depression, and loss of independence. We propose a pilot clinical trial to refine and test a novel approach for detecting patients with undiagnosed Alzheimer's disease or dementia through targeted outreach. Our goal is to maximize the benefits of early detection while minimizing harms. Innovation: We have developed the electronic health record Risk of Alzheimer's and Dementia Assessment Rule (eRADAR), which uses information in the electronic health record (EHR) to identify patients with an elevated risk of undiagnosed dementia. In addition, we have interviewed patients, caregivers, clinicians and healthcare system leaders to inform plans for implementation. Our current proposal is heavily informed by this preliminary work. We estimate that, if patients with eRADAR scores in the top 15% were targeted for assessment, we would detect nearly half of patients with undiagnosed dementia. Investigators: The PIs have expertise in dementia epidemiology, risk prediction modeling and primary care. They collaborated successfully to develop eRADAR. Co-investigators bring expertise in qualitative methods, implementation science, and health system change. Approach: We propose a pilot clinical trial in which about 50 primary care physicians at two clinics within Kaiser Permanente Washington (KPWA) will be randomly assigned to have their patients (N=~12,000) targeted for outreach based on their eRADAR scores or to usual care (control group). Our research staff embedded in the clinics will work with the primary care team to reach out to patients with high eRADAR scores, conduct a preliminary dementia assessment, make follow-up recommendations, and support patients after diagnosis. In Aim 1, we will develop and refine intervention processes in an iterative fashion with input from patients, caregivers and primary care teams. In Aim 2, we will assess eRADAR's performance, focusing on positive predictive value and dementia diagnosis rates in the intervention vs. usual care groups. In Aim 3, we will use mixed methods to assess the impact of eRADAR implementation on healthcare utilization and patient and family member experiences. Environment: KPWA is a learning healthcare system, where research shapes practice and practice shapes research. KPWA also has a strong track record of innovation utilizing the Epic EMR, which is widely used in the US, increasing the potential for dissemination. Summary: The proposed study will refine and pilot test a unique approach for targeted dementia screening in patients at high risk of having undiagnosed dementia. It will use a novel EHR-based tool and patient-centered outreach processes. This work will lay the groundwork for a full-scale clinical trial in which we will determine whether implementation of eRADAR improves care and outcomes for older adults.